Hasil untuk "Chemical technology"

Eun-Kyung Lim, Taekhoon Kim, S. Paik et al.

Ying Zhou, Jun Feng Zhang, Juyoung Yoon

A. Reddy, A. Srivastava, Sanketh R. Gowda et al.

J. Chen, Yi Ling. Tan, Chang Ming Li et al.

Hongliang Wang, Yunqiao Pu, A. Ragauskas et al.

The exploration of effective approaches for the valorization of lignin to valuable products attracts broad interests of a growing scientific community. By fully unlocking the potential of the world's most abundant resource of bio-aromatics, it could improve the profitability and carbon efficiency of the entire biorefinery process, thus accelerate the replacement of fossil resources with bioresources in our society. The successful realization of this goal depends on the development of technologies to overcome the following challenges, including: 1) efficient biomass pretreatment and lignin separation technologies that overcomes its diverse structure and complex chemistry challenges to obtain high purity lignin; 2) advanced chemical analysis for precise quantitative characterization of the lignin in chemical transformation processes; 3) novel approaches for conversion of biomass-derived lignin to valuable products. This review summarizes the latest cutting-edge innovations of lignin chemical valorization with the focus on the aforementioned three key aspects.

S. Hassan, Gwilym A. Williams, Amit K Jaiswal

Pretreatment of lignocellulosic biomass to overcome its intrinsic recalcitrant nature prior to the production of valuable chemicals has been studied for nearly 200 years. Research has targeted eco-friendly, economical and time-effective solutions, together with a simplified large-scale operational approach. Commonly used pretreatment methods, such as chemical, physico-chemical and biological techniques are still insufficient to meet optimal industrial production requirements in a sustainable way. Recently, advances in applied chemistry approaches conducted under extreme and non-classical conditions has led to possible commercial solutions in the marketplace (e.g. High hydrostatic pressure, High pressure homogenizer, Microwave, Ultrasound technologies). These new industrial technologies are promising candidates as sustainable green pretreatment solutions for lignocellulosic biomass utilization in a large scale biorefinery. This article reviews the application of selected emerging technologies such as ionizing and non-ionizing radiation, pulsed electrical field, ultrasound and high pressure as promising technologies in the valorization of lignocellulosic biomass.

B. Cravatt, A. Wright, J. Kozarich

Mohd Ali Hashim, Soumyadeep Mukhopadhyay, J. Sahu et al.

K. Nevin, T. Woodard, Ashley E. Franks et al.

ABSTRACT The possibility of providing the acetogenic microorganism Sporomusa ovata with electrons delivered directly to the cells with a graphite electrode for the reduction of carbon dioxide to organic compounds was investigated. Biofilms of S. ovata growing on graphite cathode surfaces consumed electrons with the reduction of carbon dioxide to acetate and small amounts of 2-oxobutyrate. Electrons appearing in these products accounted for over 85% of the electrons consumed. These results demonstrate that microbial production of multicarbon organic compounds from carbon dioxide and water with electricity as the energy source is feasible. IMPORTANCE Reducing carbon dioxide to multicarbon organic chemicals and fuels with electricity has been identified as an attractive strategy to convert solar energy that is harvested intermittently with photovoltaic technology and store it as covalent chemical bonds. The organic compounds produced can then be distributed via existing infrastructure. Nonbiological electrochemical reduction of carbon dioxide has proven problematic. The results presented here suggest that microbiological catalysts may be a robust alternative, and when coupled with photovoltaics, current-driven microbial carbon dioxide reduction represents a new form of photosynthesis that might convert solar energy to organic products more effectively than traditional biomass-based strategies. Reducing carbon dioxide to multicarbon organic chemicals and fuels with electricity has been identified as an attractive strategy to convert solar energy that is harvested intermittently with photovoltaic technology and store it as covalent chemical bonds. The organic compounds produced can then be distributed via existing infrastructure. Nonbiological electrochemical reduction of carbon dioxide has proven problematic. The results presented here suggest that microbiological catalysts may be a robust alternative, and when coupled with photovoltaics, current-driven microbial carbon dioxide reduction represents a new form of photosynthesis that might convert solar energy to organic products more effectively than traditional biomass-based strategies.

Meggie Hakim, Y. Broza, O. Barash et al.

D. Bhatkhande, V. G. Pangarkar, A. Beenackers

R. Overend, E. Chornet

S. K. Amit, M. Uddin, Rizwanur Rahman et al.

Food preservation involves different food processing steps to maintain food quality at a desired level so that maximum benefits and nutrition values can be achieved. Food preservation methods include growing, harvesting, processing, packaging, and distribution of foods. The key objectives of food preservation are to overcome inappropriate planning in agriculture, to produce value-added products, and to provide variation in diet. Food spoilage could be caused by a wide range of chemical and biochemical reactions. To impede chemical and microbial deterioration of foods, conventional and primitive techniques of preserving foods like drying, chilling, freezing, and pasteurization have been fostered. In recent years, the techniques to combat these spoilages are becoming sophisticated and have gradually altered to a highly interdisciplinary science. Highly advanced technologies like irradiation, high-pressure technology, and hurdle technology are used to preserve food items. This review article presents and discusses the mechanisms, application conditions, and advantages and disadvantages of different food preservation techniques. This article also presents different food categories and elucidates different physical, chemical, and microbial factors responsible for food spoilage. Furthermore, the market economy of preserved and processed foods has been analyzed in this article.

Anna Lee, J. Elam, S. Darling

Bei-Bei Zhang, B. Biswal, Jingjing Zhang et al.

Hydrothermal process is an emerging technology that contributes to sustainable production of biomass-derived chemicals, fuels, and materials. This technology uses hot compressed water to convert various biomass feedstocks including recalcitrant organic compounds in biowastes into desired solid, liquid, and gaseous products. In recent years, considerable progress has been made in the hydrothermal conversion of lignocellulosic as well as nonlignocellulosic biomass to value-added products and bioenergy to fulfill the principles of circular economy. However, it is important to assess hydrothermal processes in terms of their capabilities and limitations from different sustainability aspects so that further advances can be made toward improvement of their technical maturity and commercialization potential. The key aims of this comprehensive review are to (a) explain the inherent properties of biomass feedstocks and physio-chemical characteristics of their bioproducts, (b) elucidate related transformation pathways, (c) clarify the role of hydrothermal process for biomass conversion, (d) evaluate the capability of hydrothermal treatment coupled with other technologies for producing novel chemicals, fuels and materials, (e) explore different sustainability assessments of hydrothermal processes for potential large-scale applications, and (f) offer our perspectives to facilitate the transition from a primarily petro-based to an alternative biobased society in the context of changing climate.

S. Susarla, V. Medina, S. McCutcheon

J. Speight

Zewei Wu, Yi Liu, Sai Chen et al.

Abstract CO2-assisted oxidative dehydrogenation of light alkane is a promising and innovative technology for light olefin production; however, the interference of side reactions and sluggish reactivity of CO2 limit olefin yields. This paper describes an economically viable tandem catalytic system by coupling alkane dehydrogenation and the reverse water gas shift (RWGS) reaction, employing PtSn/SiO2 as ethane dehydrogenation (EDH) sites and nano-CaCO3 as the hydrogen acceptor for sequent RWGS. This tandem catalytic system significantly surpasses commercial CrOx- and Pt-based catalytic systems, and breaks the EDH thermodynamic equilibrium limitation, reaching 142% of the nominal equilibrium ethylene yield of non-oxidative EDH process with 96.7% selectivity under industrially relevant conditions. Experimental characterization and theoretical analysis confirm that CaCO3 mediates the pathway of hydrogen spillover that originates from adjacent PtSn/SiO2, which effectively facilitates the RWGS reaction and thus shifts the EDH toward ethylene. This tandem catalytic strategy assisted by carbonates potentially expands the palette of catalytic systems pertaining to hydrogen transfer mechanisms in CO2-involved hydrogenation or dehydrogenation reactions.

Madhusmita Swain, Durgamadhab Mishra, Gourishankar Sahoo

Abstract Nanoparticles and Nanostructured materials are playing an ever-important role in affordable healthcare, environment remediation, renewable energy, agriculture, consumer electronics, cosmetics etc. However, progress in these sectors has to be sustainable, environmentally friendly and requires sustainable synthesis process of nanoparticles and nanomaterials with net zero toxic byproducts. Therefore, green synthesis techniques are being actively pursued by researchers everywhere. When naturally occurring precursors replace industrially produced chemicals; it is always cost effective and facilitates direct as well as indirect employments to common man. Zinc oxide (ZnO) is one of the few materials which has wide spread application in all of the above sectors due to its unique physical, chemical, optical and electronic properties. In this review, various green synthesis techniques for ZnO nanoparticles used by different researchers in last 5–8 years are discussed and reviewed. In the beginning, the conventional synthesis techniques of ZnO nanoparticles are discussed briefly including ball milling, sol–gel, hydrothermal and precipitation methods. In the second part, different green synthesis techniques are discussed using various plant extracts. Particularly, the use of green tea leaf extracts in ZnO nanoparticle synthesis is discussed in detail. The factors that affect the morphology of nanomaterials are also discussed. Finally, the challenges and issues still remaining to be addressed are outlined with a conclusion. The review will be useful to researchers who want to pursue green synthesis of nanoparticles in general and ZnO in particular as beginners. It will be beneficial to biochemist, biologist, biotechnologist, environmentalist, industrialist and policy makers interested in progress towards sustainable science and technology.

Mingqian Chen, Wen Li, Taoyu Hu et al.

Abstract Quantitative, label-free monitoring of dynamic cell adhesion remains challenging. Meta-Surface Plasmon Resonance Microscopy (Meta-SPRM) is a novel platform integrating bright-field microscopy with engineered Meta-SPR nanocup arrays. This system simultaneously acquires bright-field images and Meta-SPRM signals, enabling their computational separation and co-analysis to provide multifaceted insights into cell-substrate interactions. Meta-SPRM offers sensitive, high-throughput, and long-term label-free quantification of cell adhesion strength and distribution. It captures dynamic processes like cell spreading and migration at micrometer lateral resolution. Notably, Meta-SPRM signals spatially correlate with key focal adhesion proteins (Integrin-β1, Vinculin), and an intrinsic intracellular signal polarity correlates with cell migration direction. Meta-SPRM provides a powerful, label-free tool for dynamic cell adhesion studies, overcoming limitations of traditional methods. Graphical abstract